International Journal of Molecular Sciences (Apr 2021)

Candidate Alzheimer’s Disease Biomarker miR-483-5p Lowers TAU Phosphorylation by Direct ERK1/2 Repression

  • Siranjeevi Nagaraj,
  • Andrew Want,
  • Katarzyna Laskowska-Kaszub,
  • Aleksandra Fesiuk,
  • Sara Vaz,
  • Elsa Logarinho,
  • Urszula Wojda

DOI
https://doi.org/10.3390/ijms22073653
Journal volume & issue
Vol. 22, no. 7
p. 3653

Abstract

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MicroRNAs have been demonstrated as key regulators of gene expression in the etiology of a range of diseases including Alzheimer’s disease (AD). Recently, we identified miR-483-5p as the most upregulated miRNA amongst a panel of miRNAs in blood plasma specific to prodromal, early-stage Alzheimer’s disease patients. Here, we investigated the functional role of miR-483-5p in AD pathology. Using TargetScan and miRTarBase, we identified the microtubule-associated protein MAPT, often referred to as TAU, and the extracellular signal-regulated kinases 1 and 2 (ERK1 and ERK2), known to phosphorylate TAU, as predicted direct targets of miR-483-5p. Employing several functional assays, we found that miR-483-5p regulates ERK1 and ERK2 at both mRNA and protein levels, resulting in lower levels of phosphorylated forms of both kinases. Moreover, miR-483-5p-mediated repression of ERK1/2 resulted in reduced phosphorylation of TAU protein at epitopes associated with TAU neurofibrillary pathology in AD. These results indicate that upregulation of miR-483-5p can decrease phosphorylation of TAU via ERK pathway, representing a compensatory neuroprotective mechanism in AD pathology. This miR-483-5p/ERK1/TAU axis thus represents a novel target for intervention in AD.

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